Age and Gender Differences in Functional Recovery Trajectories After Hip Fracture Among Chinese Older Adults: A 9-Year Longitudinal Study.

OBJECTIVES: To characterize trajectories of activities of daily living (ADL) difficulties before and after hip fracture among Chinese older adults and to examine effect modifications by age and gender. SETTING AND PARTICIPANTS: A prospective cohort study utilizing data from the China Health and Retirement Longitudinal Study (2011-2020), including 25,873 participants (719 with incident hip fracture). METHODS: ADL difficulties were assessed using the 6-item Katz Index of ADL scale based on patient self-report. Linear mixed-effects models examined trajectories, and interaction terms tested effect modification by age and gender. RESULTS: Hip fracture was associated with an immediate increase of 0.580 ADL difficulties (P < .001), followed by gradual annual recovery. Age significantly modified fracture impact (interaction: β = 0.033; P < .001). The 70 to 79 age group was most vulnerable, with an immediate increase of 0.908 ADL difficulties, whereas those aged ≥80 years exhibited increasing ADL disability during recovery. Male gender was protective against increasing ADL difficulties after fracture (β = -0.185; P = .023). Difficulties remained 25% above prefracture levels at 6 years after fracture. CONCLUSIONS AND IMPLICATIONS: Age and gender are critical modifiers of functional recovery after hip fracture. The vulnerability of 70 to 79 year olds and the increasing ADL disability during recovery of the oldest-old underscore the need for age-specific rehabilitation strategies in aging populations like China.